Article conveyor system

ABSTRACT

An article conveying system including a conveyor belt having a plurality of slats movable along a slider bed. A nozzle system directs a water and detergent flush along the water bed beneath the conveyor belt to remove debris. A water tank and scrap basket collect and remove the debris and direct water to a drain. The slats have lower feet which engage a pair of plastic tracks and are removable for cleaning. The system is also provided with an anti-jam device.

This is a divisional of application Ser. No. 08/372,497 filed Jan. 13,1995 abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This application is a continuation in part of copending application,Ser. No. 08/304,801 filed on Sep. 12, 1994, entitled Conveyor System.This invention relates to article moving apparatus and moreparticularly, to an improved conveyor system.

2. Summary of the Prior Art

Conveyors of numerous designs have been used in the past to transportarticles from one station to another. Known conveyors have employedendless belts, segmented slats and other elements to move objects alongtheir path of transport. Conveyors are particularly useful in foodservice applications, specifically to transport dishes, glasses andsilverware, individually or on cafeteria trays, from the cafeteria tothe dishroom. Food service conveyors are also used to transportdishware, glasses and silverware in standard dish room racks or on theconveyor belt, usually from a scraping table to a dishwashing machine.In some cases, the scraping table may form part of the conveyor toremove excess material before being conveyed to the dishwashing machine.In typical commercial kitchens, dishrooms and cafeterias, it is oftennecessary for a conveyor to transport trays, dishware and the like forconsiderable distances, during which the conveyor belt may move alongcombined linear or curved paths. In such situations, equipment must bereliable and capable of sustaining heavy duty service while maintainingsatisfactory sanitary conditions.

One type of a conventional conveyor utilizes a plurality of separatebelt slats mounted on an endless chain drive. The slats of the foregoingdesign are capable of independent motion during movement along curvesand usually undergo articulation or separation from the drive sprocketat the slider bed entrance or end of the upper conveyor run. In suchsystems, it is desirable to remove individual conveyor slats forpurposes of cleaning, replacement, repairing and maintenance. It is alsodesirable to remove the chain and belt assembly for purposes ofcleaning. The belt of known conveyors are secured to rails in a mannerthat makes them difficult to remove for cleaning, particularly alongcurved paths, while the rails adjacent the belt are fastened and notmoveable for cleaning.

Known conveyors are also deficient in circulating adequate water andsanitizing detergent beneath the upper conveyor belt and in the sliderbed trough for sufficient removal of debris. In prior systems removal ofdebris from the slider trough was done manually, while removal of debrisfrom the slat belt was separately accomplished by wash nozzles in thewash tank. Such techniques have failed to provide effective removal ofdebris. Accordingly, improvements are needed in conveyors systems toprovide effective periodic cleaning and flushing of debris from thesystem during use.

A potentially dangerous hazard also exists in prior conveyor systems atthe slider bed entrance. This is the area at which the belt slat engagesthe sprocket of the conveyor drive and where fingers of individuals andclothing can be caught causing personal injury. Articles, such assilverware and the like, can also get caught to interfere with movementof the conveyor belt and cause system damage which may require majorrepairs. Current conveyors have not satisfactorily solved the problem ofpreventing potential injury to personnel and prevent jamups at theslider bed entrance.

As is the case of any machinery undergoing heavy duty use, conveyorsrequire periodic service and replacement of parts. In the past,operative components of the conveyors, such as detergent pumps, motors,low level alarms, electrical elements, drive motors and gears, bearings,controls and the like, are usually situated within a housing in a mannerthat is not conveniently accessible for service. Such an arrangement ofthe operative components interferes with serviceability and increasesthe costs and time for repair or service.

It is, therefore, desirable to provide an improved conveyor systemhaving improved operative features relating to performance, maintenanceof cleaned sanitary conditions, safety, and serviceability.

SUMMARY OF THE INVENTION

It is an objective of the invention to provide an improved conveyorsystem for transporting articles. The conveyor system of the inventionis particularly useful in food service applications for delivery ofdishware, glasses and silverware, either individually or on trays ordish racks and the like. The conveyor mechanism herein disclosedincludes belt slats which are affixed to an endless stainless steelroller chain to create movement along a slider bed. The belt slats movealong slide rails and possess an improved design allowing for readyremoval from the slide rails for purposes of cleaning, even at curvedsections of the upper conveyor path. The design of the slats hereinfurther reduces friction along the slide rail and provides an overallimprovement in the performance of the conveyor.

The system of the invention is also provided with an improved flushingcapability through which satisfactory sanitary conditions can bemaintained during use even with extreme accumulation of debris. The topslider bed is provided with a sanitizing flush to move water and debrisalong the slider bed through water pressure and in conjunction with themotion of the conveyor chain to flush the material for discharge at acollection point. In addition, a drip pan is disposed below the lowerreturn portion of the conveyor belt and is subjected to a flush in asimilar manner as the upper slider bed. As a result of the efficientperformance of a top and lower sanitizing flush, the removal of debristrapped on the endless belt is highly effective.

A water tank at the drive end for the upper flush and at tail end forthe lower flush of the invention operates in conjunction with the upperand lower flushing systems to direct water into an external scrap basketand out the drain in a manner providing efficient water flow and removalof debris. The drive motor, gear reducer, drive chain sprockets and takeup idler of the system are all accessible through one side of a housingfor convenient servicing, a capability not found in prior conveyorsystems. Serviceability is further enhanced by removing componentsnormally requiring service from the housing to a remote location. Suchcomponents as the detergent pump and motor, low level sensor, electricalcomponents, grease fittings, and meters are all positioned at locationseasily reached for service. The bearings of each side of the slat beltconveyor are located inside the tank drive housing and are accessiblefrom the top to improve access to these components which requiremaintenance service and replacement on occasion. Thus, the inventionefficiently houses the internal operative components in so that serviceand maintenance costs and shutdown are minimized.

The dangerous conditions existing at the slider bed entrance where thebelt slat engages the sprocket are alleviated in the conveyor system ofthe invention. The articulating slats are covered by a pivotal plate andare not externally exposed. Such protection reduces the likelihood ofsilverware, fingers and clothing and the like getting caught. Moreover,the invention includes means to cease operation of the conveyor belt ifan object, such as silverware, engages the pivotal plate. Suchdeactivation of the conveyor system prevents jamup and the need of majorrepair. The unique design of the anti-jam means herein disclosed allowsobjects of a predetermined size, such as dish trays or racks, to bepushed past the slider bed entrance without interference with theoperation of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of the conveyor system of the invention;

FIG. 2 is a front elevational view of the conveyor system of FIG. 1;

FIG. 3 is an end elevational view, with parts removed, of the conveyorsystem of FIG. 1;

FIG. 4 is an end elevational view, with parts in section, taken alonglines 4--4 of FIG. 1;

FIG. 5 is an end elevational view, with parts in section, taken alonglines 5--5 of FIG. 1;

FIG. 6 is an enlarged detailed top view of the nozzle of FIG. 4;

FIG. 7 is a top plan view of a slat of the conveyor system of FIG. 1;

FIG. 8 is a front elevational view of the slat of FIG. 7;

FIG. 9 is a bottom plan view of the slat of FIG. 7;

FIG. 10 is a side elevational view of the slat of FIG. 7;

FIG. 11 is a partial elevational view, with parts broken away, showingthe drive housing and conveyor belt of the conveyor system of FIG. 1;

FIG. 12 is a side elevational view of the drive housing and wash tank ofthe conveyor system of FIG. 1;

FIG. 13 is an end elevational view, with parts in section, of the drivehousing wash tank of the conveyor system taken along lines 13--13 ofFIG. 1;

FIG. 14 is an end elevational view, with parts in section, of the drivehousing wash tank and catch pan taken along lines 14--14 of FIG. 1;

FIG. 15 is a perspective side view of the scrap basket and scrap basketholder for use with the drive housing wash tank of FIG. 14;

FIG. 16 is a side perspective view of the scrap basket holder andremovable scrap basket of FIG. 15 showing external handle foraccessibility where conveyor is behind dishtable;

FIG. 17 is a side perspective view of the scrap basket of FIG. 16 withextension handle;

FIG. 18 is a partial side elevational view of the anti-jam means deviceat the slider bed entrance of the conveyor system of FIG. 1 wherearticulation is not exposed;

FIG. 18a is a partial side elevational view of a prior art slider bedentrance of a conveyor system;

FIG. 19 is a partial side elevational view, with parts removed, of theanti-jam means device of FIG. 18 in operative relationship with themicro switch of the control circuit of the conveyor system of FIG. 1;

FIG. 20 is a partial end elevational view of the conveyor system withdrip pan, with parts in section, taken along lines 20--20 of FIG. 1;

FIG. 21 is a top partial plan view of the details of the three flushnozzles and manifold used in the drip pan of FIG. 11; and

FIG. 22 is an enlarged elevational view of the three flush nozzles andmanifold in the drip pan of FIG. 20.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1-3, there is illustrated the improved conveyorsystem of the invention, generally designated by the reference numeral2. Although the conveyor system 2 can be used to transport a wide rangeof articles from one station to another, the conveyor system 2 isparticularly useful in food service applications, specifically totransport dishware, glasses and silverware from the cafeteria to thedishroom, and in the dishroom to transport dishware, glasses andsilverware on trays or racks from the scrapping table to the dishwashingmachine and the like. The conveyor system 2 includes an endless slatbelt conveyor 4, which moves along an upper conveyor path 5 from beltexit 5a to slider bed entrance 5b. As seen in FIG. 1, the upper conveyorpath 5 extends along straight and curved sections and passes variousstations (not shown) as is needed in particular applications. Theendless slat belt 4 has a return path 5' from the slider bed entrance 5band returning to the slider bed exit 5a, as will be more fully describedlater.

The slat belt conveyor 4 is provided with a plurality of slats 6, whichare retained for movement on a driven endless chain 8 (FIGS. 3, 11, 12and 18). The endless chain 8 has conventional links 8a and moves in acentral depressed trough 9 of an elongated metal slider bed 10 thatextends along the entire upper conveyor path 5a. The slider bed 10 isformed from stainless steel, aluminum, and the like. The slider bed 10includes a pair of vertical sides 10a and a flat bed 10b surroundingtrough 9 as seen in FIGS. 3 and 4. The slats 6 are disposed for movementin the conveyor path 5 along trough 9 and a portion of the flat sliderbed 10b.

As best seen in FIGS. 2-3, 11, and 12, the slat belt conveyor 4 isdriven by a drive chain 11 through drive motor 12 and drive sprocket 13.The electric drive motor 12 is positioned beneath the conveyor belt 4 inhousing 14 at the slider bed entrance 5b. The housing 14 rests on legs14a and has vertical walls 14b and a bottom wall 14c. A wash tankenclosure 15 separates the upper portion of housing 14 from the drivecomponents, including electric motor 12. Other legs 16 support the otherportion of the conveyor system 2 (FIG. 2). The housing has removabledoor 17 to provide access to the drive components as needed,particularly if the conveyor is adjacent a wall as shown in FIG. 2. Adriven sprocket 18 engages the links 8a of conveyor chain 8 throughteeth 18a to move the slat belt conveyor 4. As seen in FIGS. 2 and 3,the driven sprocket 18 is mounted on shaft 19 mounted in bearings 19a atan upper position in housing 14. It should be apparent that the conveyorbelt 4 moves from exit 5a to slider bed entrance 5b in conveyor path 5and beneath the conveyor belt in its conveyor return path 5'. Monorails20 aid in support of the conveyor belt 4 in the return path as shown inFIGS. 2, 4, 5, and 11.

In the FIGS. 4, 5, and 7 to 10, the construction of an individual slat 6of the slat conveyor belt 4 is best illustrated. The slats 6 of theinvention are formed as a unitary member from a suitably low frictionalmaterial, such as Delrin or polyprophylene. The slats 6 each include arear upper portion 30 and a lower front portion 32, which form an upper34 shoulder extending in a swept-back orientation as seen in FIG. 7. Theshoulder 34 permits the slats 6 to undergo relative movement along thecurves of the upper conveyor path 5a and the lower return path. Thelower surface 36 of the slat 6 is flat to engage a portion of sliderrails 50. The slats 6 are provided with integral lower feet portions 38which are in the form of two integral bracket members 40 having aU-shaped configuration from the bottom (FIG. 9) and having an L-shapedconfiguration (FIG. 8) from the front. An abutment 42 is formed on eachouter side of the bracket members 40 and slopes in inwardly from thebottom to the top to create a triangular like surface configuration 44when viewing the front of the slat in FIG. 8. The lower feet portions 38include a pair of holes 46 (FIG. 9) to receive the pins 48 of theendless chain 8 to which the slat 6 is attached.

As best seen in FIGS. 4 and 5, the feet portions 38 of the slats 6 aredisposed between a pair of spaced slide rail assemblies 50 fabricatedfrom an ultra-high molecular weight polyethylene demonstrating lowfriction characteristics. The rails 50 in the straight sections of theupper conveyor path 5 have a generally rectangular cross-section 52 andare mounted on each side of slide bed trough 9. The curved sections 54(FIG. 1) of the slide rails 50 possess a modified configuration on theinner curve 54a in which a side surface 56 confronting the slat feet 38has an downwardly pacing slope 58 to engage the triangular surfaceconfiguration 44 of the slat feet 6 forming a upwardly facing slope asbest seen in FIG. 5. Such a corresponding relationship between the sidesurface 56 of rails 50 and a foot portion 38 creates contact on one sideto maintain the slat 6 in place around curves. The design also allowsbelt assembly 4 to be easily pulled out for cleaning even around curvedportions where difficulties exist in the past when removing slats oncurves. The hollow portions 58 in bracket members 40 allow easy accessfor a tool, such as a screwdriver, to be placed between the slat footand the chain 8 for ease of removing a slat 6 at any top slider point inthe conveyor path 5.

A plurality of slide rails 50, in sections of approximately four feet,are affixed end to end in the trough 9 of the slider bed 10 by use ofbolts 60 having an excessive length and being in oversized holes 62 toform a continuous pair of rails 50. The excessive length of the bolts 60with an unthreaded lower portion 60a allows the slide rails 50 to beraised from the slider bed 10 in a captive relationship for ease ofcleaning. The enlarged lower end 60b prevents removal of rails 50 fromthe bed 10. The oversized holes 62 on the bottom of the slider bed 50allows water to drip as illustrated in FIGS. 4 and 5 to the bottom ofthe conveyor belt 6 riding in the lower return path 5' on the returnmonorail 20, roller, or other type of return system during the topslider bed flush to be described later.

As best seen in FIGS. 4, 5, 11, and 12, the monorail slide rails 20 ofreturn path 5' are disposed in corresponding relationship below portionsof the upper conveyor path 5. The rails 20 are suitably affixed to theconveyor housing and include sloped upward facing surfaces 64 in thesides 66 confronting triangular portions 44 of the slat feet 38, suchthat the triangular abutment 42 of the slats 6 are locked in an invertedposition on the lower monorail slide rails 20. The lower returning sliderails 20 are also formed from an ultra-high molecular weightpolyethylene.

Referring to FIGS. 1, 4, and 6, the top flush nozzle 68 for the sliderbed 10 is best illustrated. The top flush nozzle 68 is positionedbeneath the slider bed 10 at a location in the vicinity of the slat beltexit 5a at the beginning of the upper conveyor path 5. The nozzle 68 issuitably mounted beneath a port 69 in the slider bed 10 to deliver asanitizing spray of water and detergent into trough 9 of slider bed 10beneath the slats 6. Additional nozzles (not shown) may be spaced asneeded approximately every 16 to 30 feet.

The flush is delivered by nozzle 68 at predetermined intervals, such as,for 15 to 30 seconds every 15 to 30 minutes or as otherwise required.The pressure of the flush acts to push water and debris along the sliderbed 10 in conjunction with the relative movement of the conveyor 4 dueto the close proximity of the belt 4 with the pan and acting as apropellant. A trough 70 is provided near the slider bed entrance 5a ofthe conveyor belt 6 as shown in FIG. 13.

As seen in FIGS. 13, 14, 15, 16, and 17, the water and debris aredirected from the slider bed 10 through trough 70 into the water tank72. (FIG. 13). The water and debris are then routed from the water tank72 through an outlet (not shown) to a scrap basket 74, having an opentop 74a and perforated bottom 74b, and out the drain 75 (FIG. 2). Thescrap basket 74 is slidably mounted in a holder 76 externally of thewater tank 72 and is removable therefrom as seen in FIG. 16. The holder76 includes an open top 76a and a pair of upper flanges 76b. Bottomsections 76c also provides support of the bottom of scrap basket andprovides outlet to drain 75. Both upper flanges 76b and lower sections76c are angularly oriented in relation to the water tank 72. The scrapbasket 74 is angularly oriented in sliding relationship on the holder 76to permit easy removal and to direct debris out of the normal waterstream to assure a good water flow and to facilitate removal of debris.The removability of scrap basket allows for easy emptying of debriscollected by scrap basket 74. An extension handle 78 is mounted on scrapbasket 74. The extension handle 78 permits easy removal of the scrapbasket 74 even when the conveyor belt drive and water tank are in aninaccessible location as necessitated by application requirements.

As seen in FIGS. 11, 20, 21, and 22, a bottom drip pan flush is providedin drip pan 80 lying below the conveyor return path 5'. The drip pan 80having a bottom 80a and upright spaced sides 80b is disposed beneath asubstantial portion of the conveyor return path 5. A sanitizing spray ofwater and detergent is delivered upward through drip pan 80 throughthree nozzles 82 (FIGS. 21 and 22) disposed in fluid communication witha manifold 83. A water inlet 84 is coupled to the manifold 83 to deliverwater and detergent to manifold 83 under pressure. The nozzles 82deliver the flushing solution into the drip pan 80 under pressure topush water and debris along the drip pan 80 to the tail end or bed exitof the conveyor. The drip pan 80 receives any debris not removed by thetop flush. The water spray from nozzles 82 carries the debris in thedrip pan 80 to the bed tail end for collection in a water tank and scrapbasket (not shown) of similar design as water tank 15 and scrap basket74 as previously described.

As seen in FIGS. 18 and 19, the conveyor system 2 includes a low profileslider bed entrance 90 in which the portion 92 of the slider bed 10covers the slats 6 as they articulate or open away at the drivensprocket 16. As seen in FIG. 18a, prior art articulating slats areexposed from above at area 92a without an enclosure or cover over whichthey open away from the sprocket. Such an area of articulation ishazardous to personal and small objects may be caught. In FIGS. 18 and19 showing the invention, the covering portion 92 is covered by asection of the slider bed 10 or the anti-jam mechanism to be described.By covering the articulating slats, the likelihood of fingers,silverware and other small objects getting caught is reduced. Ananti-jam mechanism 100 is also provided at the slider bed entrance andacts immediately to disrupt operation of the conveyor system 2 if smallobjects are caught. Although the anti-jam mechanism 100 is shown in FIG.18 where portion 92 of the slider bed covers the articulating slats; itis within the scope of the invention to use the anti-jam mechanism 100when the slats articulate and are uncovered as illustrated in FIG. 18a.The anti-jam mechanism 100 includes a pivotal plate 102 mounted forpivotal movement about shaft 104. A lever 106 is affixed to the plate102 and acts to contact an actuator 108 of an electrical micro-switch(FIG. 19). The micro-switch 110 is operatively connected to theelectrical control circuit (not shown) of motor 12 of the conveyorsystem 2. The plate 102 is selected to be of a length so that it is notpivoted upwards when larger items, such as racks, trays, plates and thelike, are being conveyed. However, as smaller items, such as silverware,are contacted, the leading edge of the plate 102 engages the item andthe plate 102 is moved upward to terminate operation of the system.Thus, jamups caused by smaller items getting caught in the slider bedentrance are alleviated without damage to the equipment. In FIG. 19, amagnetic bar 102a is fastened to the pivot plate 102 to engagesilverware and prevent it from falling into the wash tank.

In FIG. 2, the detergent tank 100 and detergent pump 103 respectively inhousing 104 and 106 for the slider bed flush are shown mounted remotefrom housing for easier service. The pump 102 delivers detergent tofluid conduits (not shown) added to the water to be delivered to thenozzle 68. The drive motor 12 and associated drive element as well aswater tank 72 are mounted with one side accessibility in housing 14.

What is claimed is:
 1. A conveyor system for conveying articles ofvarying sizes comprisingendless belt means movable between first andsecond positions respectively along an upper conveyor path for carryingthe articles of various configurations and a lower return path, saidsecond position being located adjacent the transition between said upperconveyor path and said lower return path, drive means for moving saidendless belt, detection means mounted adjacent said second position at aposition beyond said upper conveyor path, said detection means beingcoupled to said drive means and being responsive to articles smallerthan a predetermined size to terminate movement of said endless beltdrive for preventing jams at said second position, said detection meansincludes a unitary detection element extending substantially the widthof the conveyor path and said detection element being mounted formovement upon contact with an article of predetermined size.
 2. Theconveyor system according to claim 1 wherein said detection element ispivotally mounted adjacent said second position about a horizontal axis,said detection element being caused to move from a generally horizontalorientation to a generally upright position when said detection elementcontacts the article of predetermined size.
 3. The conveyor systemaccording to claim 2 wherein said detection means includes switch meanscoupled to said drive means to cease movement of said endless beltmeans.
 4. The conveyor system according to claim 2 wherein said drivemeans incudes a rotatably mounted sprocket, said endless belt havingslats having lower means engaging said sprocket adjacent in an area ofarticulation at which said slats are separated from said sprocket, saiddetection element covering said area.
 5. A conveyor systemcomprisingendless belt means movable between first and second positionsrespectively along an upper conveyor path and a lower return path, saidsecond position being located adjacent the transition between said upperconveyor path and said lower return path, drive means for moving saidendless belt, detection means mounted adjacent said second positionbeyond said conveyor path, said detection means being coupled to saiddrive means and being responsive to articles smaller than apredetermined size to terminate movement of said endless belt drive forpreventing jams at said second position, said detection means includes adetection element mounted for movement upon contact with an article ofpredetermined size, wherein said detection element includes a magnet forengaging metallic elements.
 6. A conveyor system comprisingendless beltmeans movable between first and second positions respectively along anupper conveyor path and a lower return path, said second position beinglocated adjacent the transition between said upper conveyor path andsaid lower return path, drive means for moving said endless belt,detection means mounted adjacent said second position beyond saidconveyor path, said detection means being coupled to said drive meansand being responsive to articles smaller than a predetermined size toterminate movement of said endless belt drive for preventing jams atsaid second position, said detection means includes a detection elementmounted for movement upon contact with an article of predetermined size,said detection means having means for retaining an article smaller thanpredetermined size from dropping downward.
 7. The conveyor systemaccording to claim 6 wherein said means for retaining an object includesa projecting bar.
 8. The conveyor according to claim 6 wherein said baris a magnet.